Its no failure by steemconnect directly. steemconnect generally does everything right first of all.
The problem is, I don't have much choice to include SPN in steemit.com.
I decided for an iframe solution, 6 months ago ^^ ... the problem is now, steemconnect does not allow to use this in an iframe. This procedure is correct for the first step but I don't get out of the frame that easily.
so the problem is more of a general nature, It is the interplay between steemit.com, steempunknet and steemconnect ^^ in v 0.14 i fix it. but it's just a workaround right now. i need to change that asap.